Foil forming device

ABSTRACT

A MACHINE AND METHOD IS DESCRIBED FOR FORMING SHAPES IN PREFERABLY ELONGATED WORKPIECES WHICH ARE FIXEDLY MOUNTED BETWEEN TWO END BRACKETS ON A BED. THE MACHINE INCLUDES A PAIR OF ARCUATELY SHAPED FORMING TOOLS. ONE OF THE TOOLS HAS A DESIRED SHAPE WHICH MATES WITH THE SHAPE OF THE OTHER TOOL. THE TOOLS ARE MOUNTED ON EITHER SIDE OF THE MATERIAL BEING FORMED AND ARE ROTATED SIMULTANEOUSLY AS THE CARRIAGE TO WHICH THEY ARE MOUNTED MOVES ALONG THE LONGITUDINAL AXIS OF THE WORKPIECE. THE ARCUATE RADII OF THE FORMING TOOLS ARE AT A DIMENSION CONSIDERABLY LESS THAN THE OVER-ALL LENGTH OF THE WORKPIECE AND THE MOVEMENT OF THE CARRIAGE AND THE ROTATION   OF THE TOOLS IS SO DESIGNED THAT A COMPLETE ARCUATE ROTATION OF THE TOOL IS COMPLETED AS THE TOOL IS MOVED ALONG THE ENTIRE LENGTH OF THE MATERIAL, THUS FORMING THE DESIRED SHAPE.

Nov. 16, 1971 w. A. SWANSON FOIL FORMING DEVICE 2 Sheets-Sheet 1 Filed Dec. 20, 1968 INVENTOR. /LF'OQD .4. swpusord' Nov. 16, 1971 w. A. SWANSON 3,620,065

FOIL FORMING DEVICE Filed Dec. 20, 1968 1 2 Sheets-Sheet 2 [NV/LN'IUR. WILFOZD H Sta/0105010 BY ,EMZM 5 QT OQJEY United States Patent "ice 3,620,065 FOIL FORMING DEVICE Wilford A. Swanson, 11609 Pendleton St., Sun Valley, Calif. 91352 Filed Dec. 20, 1968, Ser. No. 785,580

Int. Cl. B21d 11/02 US. Cl. 72-297 10 Claims ABSTRACT OF THE DISCLOSURE A machine and method is described for forming shapes in preferably elongated workpieces which are fixedly mounted between two end brackets on a bed. The machine includes a pair of arcuately shaped forming tools. One of the tools has a desired shape which mates with the shape of the other tool. The tools are mounted on either side of the material being formed and are rotated simultaneously as the carriage to which they are mounted moves along the longitudinal axis of the workpiece. The arcuate radii of the forming tools are at a dimension considerably less than the over-all length of the workpiece and the movement of the carriage and the rotation of the tools is so designed that a complete arcuate rotation of the tool is completed as the tool is moved along the entire length of the material, thus forming the desired shape.

This invention relates to apparatus and method for forming desired shapes in workpieces and more particularly to a novel and improved foil forming device which draws the material into a desired shape.

Prior art forming machines have heretofore formed materials into shapes by pressing or bending. Further, where shapes are sought to be of an intricate configuration, they have been generally extruded through dies. A disadvantage of the pressing and bending method is that some materials because of the molecular structure have a tendency to spring back to their original position. The technique of extruding is quite costly as compared to other known methods.

It is therefore an object of the invention to provide a novel and improved apparatus for forming shapes in elongated workpieces.

Another object of this invention is to provide a novel and improved apparatus for the draw forming of a sheet material into a desired shape.

Another object of this invention is to provide a novel and improved-forming machine which can vary the shape of a strip of material as it is being formed and which is especially well adapted to form an object such as a propeller blade for a helicopter.

With these and other objects in view, the invention consists in the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a perspective view of a draw forming machine.

FIG. 2 is a section view of the draw forming machine showing the ultimate positioning of the forming die as it is moved along the workpiece.

FIG. 3 is a section view taken along the line 3-3 of FIG. 2.

FIG. 4 is a section view taken along the line 44 of FIG. 2.

FIG. 5 is a perspective view of the forming die of one embodiment of the invention at the beginningof the forming operation.

3,620,065 Patented Nov. 16, 1971 FIG. 6 is a perspective view of the forming die at the completion of a forming operation.

FIG. 7 is a view taken along the line 77 of FIG. 1 illustrating a method of driving the forming tools along the workpiece.

FIG. 8 is an alternative drive mechanism for the forming dies; and

FIG. 9 is another alternative drive mechanism for the forming dies.

Briefly described, the present invention comprises a machine for forming a desired shape in a workpiece. The machine includes an elongated bed having a pair of end brackets disposed in spaced relationship on opposite ends of the bed and includes means for restraining a workpiece between the two end brackets of the elongated bed. A carriage is disposed upon the bed and includes a driver for longitudinally moving the carriage along the longitudinal axis of the workpiece. A pair of arcuate forming tools is provided, one above and one below the workpiece, the forming tools being mounted on the carriage. A connection from the driver to the tools causes acruate rotation of the tools in opposing directions along the workpiece as the carriage completes a movement along the axis of the workpiece.

DESCRIPTION OF A CHOSEN EMBODIMENT In FIG. 1 there is shown a work bed indicated generally by the numerial 10 which is supported by a pair of standards 12 and 14 disposed on either end of the work bed 10. For this embodiment, the work bed -10 is shown as being elongated and having a pair of guide rails 16 and 18 extending between brackets 20 and 22 which extend upwardly from the work bed 10. A pair of clamps 24 and 28 are coupled to the brackets 20 and 22, respectively, to hold a workpiece 30 therebetween. It is this workpiece 30 which is to be shaped into the desired form.

A practical application of this invention is to draw, for example, a helicopter blade which has one end substantially fiat and the other end which is U-shaped. The progression from the flat end to the U-shaped end should be uniform from one end to the other. To be certain that when drawn the workpiece 30 will hold its shape, it is generally placed under stress lengthwise to a 2% to 3% elongation, thus making the material more adaptable by rearranging the molecules. After the material has been shaped by the drawing process of this invention, it does not have a tendency to spring back to its original shape. Means are provided to place the tension on the workpiece or blade 30 by having the clamp 24 coupled to a plate 32 which in turn is threadably mounted to the end bracket 20 by the bolts 33. The clamps 24 and 28 may be the conventional C-clamps well-known to those skilled in the art.

A carriage 34 is mounted on the bed 10 and is guided along the longitudinal axis thereof on the guide rails 16 and 18. How the carriage 34 is moved along the guide rails 16 and 18 on the bed 10 is shown in FIG. 7, for example, wherein a motor 36 is mounted on the carriage 34 and has a pinion 38 rotated by the motor 36 which engages a rack 40 affixed to the bed 10. As the motor 36 causes the pinion 38 to rotate and engage the rack 40, the carriage 34 will move from one end of the bed 10 to the other.

To facilitate shaping of the workpiece 30 a pair of forming tools 50 and 52, best shown in "FIGS. 5 and 6, are provided on the carriage 34. For this example, it is desired to shape the workpiece 30 from a substantially flat end 56 to a curved U-shaped end 58, as "best shown in FIGS. 3 and 4. This particular shape is most desirable for the shape of blades on helicopters. The particular shaping is shown in this embodiment as exemplary only,

and it should be understood that various other shapes can be made. The shape of the dies 60 and 62 in the forming tools 50 and 52, respectively in this embodiment is arcuate or quarter-circular. The die 60 is concave and tapers from a thick concave portion to a thin concave portion as shown in the section view of FlG. 2. The die 62 is convex and has a taper therein to match that of die 60.

Means are provided in the form of a gearing arrangement to rotate the forming tools 50 and 52 whereby to complete an arcuate rotation (one-fourth turn) while the carriage 34 travels the entire distance along the guide rails 16 and 18 from one end of the workpiece 30 to the other. The length of the curved portion of the arcuate forming tools is on a predetermined ratio, the tool being caused to drag along the material 30, thereby to create an ironing effect on the workpiece. Due to the presence of the 2% to 3% tensile stress applied along the longitudinal axis of the workpiece, the molecules of the material are rearranged and set by the ironing process as the tool is drawn along the workpiece 30 to, in effect,

draw-form the material.

FIG. 5 shows the relative positions at the start of the drawing and forming process of the forming tools 50 and 52, while FIG. 6 shows the positions at completion of the drawing and forming operation, whereby the end portion of the material is completely U-shaped in contrast to the fiat shape at the beginning of the operation. FIG. 2 shows the start and finish positions of the forming tools 50 and 52 and the extended skirt edge protruding down from the material 30 as indicated by the reference character 31. The start and finish operation is again shown in FIGS. 3 and 4 in section view.

A method of driving the carriage 34 along the bed it) at its desired speed to assure the desired rotational speed is shown in FIG. 7 whereby the forming tool 50 is mounted on a shaft 70 which is rotatably mounted in turn in the carriage 34. A gear 71 is mounted to rotate with the shaft 70. A sprocket 72 is mounted on a shaft 73 and has an idler gear 75 connected in the train of gears. The forming tool 52 is mounted on the carriage 34 by the shaft 74 on which a sprocket 76 is mounted. Connected between the sprockets 72 and 76 is a chain 77 for causing similar motion between the shafts 70 and 73. The effect of the idler gear 75 causes the shafts 70 and 74, and the tools 50 and 52 connected thereto to rotate in opposite directions. A gearing arrangement 78 is provided to assure the proper speed of the rotation of the forming tools 50 and 52 as the carriage progresses along the bed 10. The gearing arrangement 78 is driven by a gear 80 which is engaged with a rack 82, similar to the rack 40, and extends the distance of the workpiece 30. Thus, as the motor 36 moves the carriage 34 along the bed 10, the rack 82 causes the gear 80 engaged therewith to rotate the Shafts 70 and 74 through the gearing arrangement 78.

A typical example of movement of the carriage 34 and rotation of the tools 50 and 52 is to provide a ten to one gearing ratio whereby the forming tools 50 and 52 make a turn as the carriage travels 10 times the distance of the arc of the forming tools 50 and 52. Other ratios, of course, can be provided depending upon the length of the workpiece 30.

An alternate embodiment is shown in FIG. 8 wherein a screw shaft 86 extends throughout the breadth of the machine, as exemplified by the bed 10. The screw shaft is mounted upon conventional pillow blocks (not shown) and provided with a suitable conventional drive. An arm 88 is pivotally mounted on the threaded carriage 90 by means of an appropriate pivot pin 92. On the arm 88 is a cam follower in the form of a grooved wheel 94 which fits upon a mating track 96 which is Slanted slightly downwardly in the direction in which the carriage 9t] progresses. The forming tool 52 is firmly fixed to an arm 98 and is also pivotally mounted to the pivot 92, The forming tool 52 is moved by rotating the screw shaft 86 which causes it to advance in a desired movement upon the shaft 86. At the same time, the grooved wheel 94 is riding on the same track 96 at the high end which is adjacent the left side of the machine, for example. The screw shaft 86 is then rotated by appropriate means and as a result of the threaded engagement of the shaft 86 with the threaded bore within the carriage 90, the carriage is advanced progressively along the shaft 86 from left to right. At the same time, the grooved wheel 94 rolls along the cam track 96, the convex side 60 engages the concave side 62 of the forming tools 50 and 52 respectively with the workpiece.

With reference now to FIG. 9 there is shown still a further method of rotating the forming tools 50 and 52 as the carriage 34 progresses along the work bed 10. A rack 82 engages a pinion which in turn engages a pair of gears 100 and 102, whereby the gear 100 rotates the forming tool 52 and the gear 102 rotates the forming tool 50 in opposite directions. The forming tools 50 and 52 are shown in FIG. 9 in a broken away section for clarity to illustrate the gearing arrangements. The ratio between the gears 100 and 102 and that of gear 80 should be of the same ratio to provide a complete one quarter revolution of the forming tools 50 and 52 as the carriage 34 progresses along the work bed 10.

A further arrangement (not shown) is one in the form of independently matched electrical motors coupled to drive each tool in the opposing direction and thus eliminate the gearing arrangements described herein. A third motor can be utilized to drive the carriage 34 in a manner synchronized with the tool driving motor to provide the speed ratio heretofore mentioned.

While there has been shown but one preferred embodiment of this invention, it should be understood that many modifications and alterations are contemplated and still remain within the spirit and scope of this invention.

What is claimed is:

l. A machine for forming a desired shape in a workpiece comprising:

an elongated bed having a pair of end brackets on opposite ends of said elongated bed, said brackets having positions fixed with respect to transverse and rotational movement,

means for securing the workpiece to the end brackets in fixed position, at least one of said brackets being movable endwise for setting up tension in said Work piece,

a carriage operably mounted on the bed for longitudinal movement along the longitudinal axis of the Workpiece throughout the length of said workpiece which is to be worked,

a pair of arcuate forming tools having interfitting complementary surfaces, each of said tools being rotatably mounted on said carriage and having a positive drive therebetween, said tools being adapted to travel with the carriage and being rotatable at a circumferential rate slower than the rate of travel of the carriage to complete an arcuate rotation as the carriage completes a course of travel along the axis of the workpiece.

2. The machine defined in claim 1 and further comprising:

a rack disposed along the longitudinal axis of said bed,

and

a gear rotatably mounted on said carriage and being in a rotatably engaged relationshi with said rack.

3. The machine defined in claim 1 and further comprising: means coupled to said pair of arcuate forming tools for imparting opposite rotational movement to said tools.

4. The machine as defined in claim 3 wherein said means includes:

a first gear rotatably mounted on one of said pair of tools,

a second gear rotatably mounted on the other one of said pair of tools and being in engagement with said first gear, and

means engaging said second gear for rotating said second gear as said carriage moves along said bed.

5. A machine for forming a desired shape in a workpiece comprising:

an elongated bed having a pair of end brackets on opposite ends of said elongated bed,

means for restraining the workpiece between the end brackets,

a carriage operably mounted on the bed for longitudinal movement along the longitudinal axis of the workpiece,

a pair of arcuate forming tools having interfitting complementary surfaces, each of said tools being rotatably mounted on said carriage and having a positive drive therebetween, said tools being adapted to travel with the carriage and to complete an arcuate rotation as the carriage completes a course of travel along the axis of the workpiece,

means coupled to said pair of arcuate forming tools for imparting opposite rotational movement to said tools,

a first gear on one of said pair of tools,

an idler gear rotatably mounted on said carriage and being in engagement with said first gear,

a sprocket in rotatable engagement with said idler gear,

a second sprocket on the other of said tools, said sprockets being rotatably mounted on said carriage, and

a positive drive connecting said first sprocket and said second sprocket.

6. The machine as defined in claim 1 and further comprising: guide rails disposed along said longitudinal axis of said elongated bed and being in guiding engagement with said carriage.

7. The machine as defined in claim 1 and futher comprising:

a pair of guide rails disposed along the longitudinal axis of said elongated bed and being-in guiding engagement with said carriage,

a rack disposed along the longitudinal axis of said bed and being parallel with said guide rails, and a gear rotatably mounted on said carriage and being in a rotatably engaged relationship with said rack.

8. The machine as defined in claim 1 and further comprising: means for imparting movement of said carriage along the longitudinal axis of said bed.

9. A machine for forming a desired shape in a workpiece comprising:

an elongated bed having a pair of end brackets on opposite ends of said elongated bed,

means for restraining 'the workpiece between the end brackets,

a carriage operably mounted on the bed for longitudinal 6 movement along the longitudinal axis of the workpiece,

a pair of arcuate forming tools having interfitting complementary surfaces, each of said tools being rotatably mounted on said carriage and having a positive drive therebetween, said tools adapted to travel with the carriage and to complete an arcuate rotation as the carriage completes a course of travel along the axis of the workpiece,

one of said pairs of arcuate forming tools having a concave portion tapered in its rotational direction and the other of said forming tools having a convex portion tapered in its rotational direction, said convex portion having a taper which matches the taper of said concave portion.

10. A machine for forming a desired shape in a workpiece comprising:

an elongated bed having a pair of end brackets on opposite ends of said elongated bed,

means for restraining the workpiece between the end brackets,

a carriage operably mounted on the bed for longitudinal movement along the longitudinal axis of the workpiece,

a pair of arcuate forming tools having interfitting complementary surfaces, each of said tools being rotatably mounted on said carriage and having a positive drive therebetween, said tools being adapted to travel with the carriage and to complete an arcuate rotation as the carriage completes a course of travel along the axis of the workpiece,

means for imparting movement of said carriage along the longitudinal axis of said bed, and

means coupled to said pair of arcuate forming tools for imparting opposite rotation therebetween as said carriage moves along said bed at a speed proportionately less than the speed of said carriage,

References Cited UNITED STATES PATENTS 2,680,392 6/1954 Gaved 29-1568 2,872,964 2/ 1959 Hollis 72-297 1,046,020 12/1912 Rhodes 72210 3,274,816 9/1966 Held 72-189 3,240,045 3/1966 Sellars et a1. 72205 3,330,145 7/1967 Adolphi 72274 CHARLES W. LANHAM, Primary Examiner M. J. KEENAN, Assistant Examiner 

